Digital cameras and optical imaging devices employ image sensors. Image sensors convert optical images to digital data that may be represented as digital images. An image sensor includes an array of pixel sensors and supporting logic. The pixel sensors of the array are unit devices for measuring incident light, and the supporting logic facilitates readout of the measurements. Image sensors often manifest as charge-coupled devices (CCDs), complementary metal oxide semiconductor (CMOS) devices, or back side illuminated (BSI) devices.